This invention relates to an outputting apparatus, an outputting method, a recording apparatus, a recording method, a reproduction apparatus, a reproduction method and a recording medium by which various information signals such as, for example, an audio signal and/or a video signal or computer data can be recorded.
In recent years, as digital contents such as the Internet, compact discs (CD) and digital video discs (DVD) are spread, infringement on copyrights by illegal copying of digital contents has become into question. As a countermeasure to this problem, it has been proposed to add information for copying control to digital contents and use the information to prevent illegal copying.
Various controlling methods for preventing copying have been proposed and include a method which does not permit copying at all depending upon an information source and another method which permits copying only once but inhibits copying from a copy from an original, that is, a copy controlling system of generation limitation. The former is applied to original software which is produced and sold by a contents maker such as, for example, a DVD-ROM (Digital Video Disc-Read Only Memory). The latter copy controlling method of generation limitation is applied, for example, to information broadcast from broadcasting media.
The latter copy controlling method of generation limitation is demanded to allow the proprietor of the copyright to control the copy generation effectively. Several copying controlling methods which allow such management of the copy generation have been proposed and include a SCMS (Serial Copy Management System) for an audio signal, a CGMS (Copy Generation Management System) for a video signal and a method which makes use of an electronic watermark technique.
The SCMS system performs serial copying control using a copying inhibition/permission flag or using a category code representative of a type of a digital audio system such as, for example, a CD (compact disc) or a DAT (digital audio tape) to permit digital copying only once.
More particularly, according to the SCMS method, generation limitation control of copying of a digital audio signal can be performed based on SCMS information including a copy inhibition/permission flag and a category code transmitted together with the digital audio information such that copying of the digital audio signal in one generation is permitted, but the copied digital audio signal cannot be copied any more.
Meanwhile, according to the CGMS method, for example, where it is applied to an analog video signal, additional information of 2 bits for copying control is superposed in a particular one horizontal section in a vertical blanking period of the analog video signal, but where it is applied to a digital video signal, additional information of 2 bits for copying control is added to and transmitted together with digital video data.
The information of 2 bits used in the CGMS method (such information is hereinafter referred to as CGMS information) is defined such that it has the following significance:
“00” . . . copying is permitted
“10” . . . copying is permitted once (copying is permitted only for a generation)
“11” . . . copying is inhibited (absolute inhibition of copying)
When the CGMS information added to video information is “10”, a recording apparatus for the CGMS determines that copying recording of the video information is permitted, and executes recording of the video information. Thereupon, however, the recording apparatus rewrites the CGMS information to “11” and adds the rewritten CGMS information to the recorded video information. On the other hand, if the CGMS information added to video information to be recorded is “11”, then a recording apparatus for the CGMS determines that copying recording of the video signal is inhibited, and does not execute recording of the video information.
On the other hand, according to electronic watermark processing, information as noise is embedded in a portion which is present in video data or music data and is not significant on the perception of a human being, that is, a portion which is not redundant to music or an image. Additional information embedded in video data or music data by such electronic watermark processing cannot be removed readily from the video data or the music data. Meanwhile, even after filtering processing or data compression processing is performed for the video data or music data, the additional information of the embedded electronic watermark is detected from within the video data or music data.
In the copying controlling method which employs such an electronic watermark process as described above, the additional information to be embedded is defined so as to represent the four conditions that    (1) “copying is permitted (Copy Free)”,    (2) “copying is permitted only once (copying is permitted for only one generation) (Copy Once)”,    (3) “copying is inhibited any more (No More Copy)”, and    (4) “copying is inhibited absolutely (Never Copy)”, and represents a copy generation and a copying limitation condition of audio data or music data on which the electronic watermark information is superposed.
The (1) “copying is permitted (Copy Free)” represents that free copying of the music data or video data is permitted. The (2) “copying is permitted only once (copying is permitted by only one generation) (Copy Once)” represents that copying of the music data or video data is permitted only once. The (3) “copying is inhibited any more (No More Copy)” represents that the music data or video data are a copy of music data or video data in the condition of (2) that “copying is permitted only once” and are inhibited from being copied any more. The (4) “copying is inhibited absolutely (Never Copy)” represents that any copying is inhibited.
When the electronic watermark information superposed on video data or music data is “copying is permitted only once (Copy Once)”, a recording apparatus which can effect electronic watermark processing, that is, which can effect copying limitation processing, determines that the video data or music data can be copied and thus executes recording. Upon such recording, however, the electronic watermark information which has been rewritten to “copying is inhibited any more (No More Copy)” is superposed on the recorded video data or music data. On the other hand, if the electronic watermark information superposed on video data or music data to be recorded is “copying is inhibited any more (No More Copy)”, then a recording apparatus which can effect electronic watermark processing determines that copying recording of the video data or music data is inhibited, and does not execute recording.
In this manner, copying generation limitation control is performed by such copying generation limitation methods such as the SCMS method, the CGMS method and the method which employs an electronic watermark process such that an information signal of audio data and/or video data can be copied within such a range of personal use that it is copied and utilized in a home. However, since copying of the copied information signal is inhibited, the copied information signal is prevented from being copied successively so that the benefit or the right of the proprietor of the copyright of the information signal may not be infringed illegally.
Where copy generation limitation control of an information signal is performed using the SCMS method, the CGMS method or the method which employs an electronic watermark process, copying of a copied information signal onto a further recording medium is prevented. In other words, production of a copy of the second generation from a copy of the first generation is inhibited. However, there remains a problem that copying of the first generation is performed any number of times. More particularly, there is a problem that, for example, an original information signal provided from a contents maker and recorded on a CD or a DVD can be copied unlimitedly from the recording medium.
A possible countermeasure to the problem just described is to stop using such a copying generation limitation method as described above which involves the risk of production of a large number of copies from an information signal and provide an information signal in the form of a copy inhibiting disc copying of whose information signal is inhibited from the beginning.
However, where an information signal is provided in the form of a copy inhibiting disc, although the right of the proprietor of the copyright of the information signal can be protected with certainty, a user of the information signal cannot utilize the target information signal except from the copy inhibiting disc and thus submits to an excessively great limitation. Consequently, the countermeasure is not preferable.
For example, with regard to a copy inhibiting disc, such a manner of enjoyment of music as to select only favorite music data from a CD, copy the selected music data onto a magneto-optical disk of a small size called MD (Mini Disc; trade mark), a cassette tape, a semiconductor memory or the like and enjoy listening to them using a car stereo apparatus or enjoy listening to them on an electric car for commuters using a portable reproduction machine, as is performed within a range of personal copying, is subject to limitation.
Meanwhile, if the reproduction speed or the recording speed of an audio signal or a video signal is augmented, then copying of a target audio signal or video signal can be copied at a higher speed onto a recording medium. In this instance, since the target information can be copied in a shorter time, there is the possibility that a large number of recording media may be produced on which the same information signal is copied. Where such a large number of copied information signals are sold, the proprietor of the copyright of the information signal suffers a large amount of damage.
Particularly where a general purpose apparatus such as a computer which can effect various information processing is involved, it can copy an information signal readily and at a high speed from its characteristic. Further, since distribution and reception of an information signal through a network can be performed comparatively readily, there is a high degree of possibility that a large number of copies of the same information signal may be produced.
Thus, a copying limitation method is available wherein, when an information signal is to be copied, not such copying generation limitation control as described above is performed, but identification information of a copied information signal is stored for each recording apparatus and each recording apparatus does not copy an information signal of the same identification information as the information stored already in the recording apparatus. In other words, the copying limitation or controlling method permits only one time of copying for each information signal and for each recording apparatus.
However, where only the copying controlling method described above is employed, since copying of any information signal is permitted only once for each recording apparatus, any user of the information signal submits to new limitation in regard to copying of the information signal. For example, although, where the copy generation limitation method is employed, copying of an information signal recorded on an original recording medium such as a CD or a DVD can be performed any number of times, such copying is permitted only once by the copying limitation method. Therefore, copying of an information signal within a range of personal utilization is subject to limitation and the convenience to the user of the information signal is narrowed.